I am a firm believer in avoiding food fads.

When I was growing up, potatoes suddenly stopped being a healthy food choice and became a sinful indulgence.  Apparently all obesity was caused by them. (Oh, no, it couldn’t be the 4 cans of Pepsi a day or the bag of chips at bedtime, it must be the spuds…)

Then there was the “no eggs” craze. “Nature’s perfect food” suddenly became “poison-in-a-shell.” Science had discovered a link between cholesterol and heart disease, and since eggs were just loaded with the stuff they must be bad for you!

Nowadays everyone is jumping on the high-fiber bandwagon. While undoubtedly most of us do need more fiber in our diets, the tough insoluble fiber from wheat bran gets center stage, while the mixed and soluble types of fiber from oats, barley, and fresh fruits and vegetables only get honorable mention.

Bottom line -- when the culture suddenly tells you that some food is either bad for you or a cure all you should be very, very suspicious.

Let’s start with some truths about potatoes.

Potatoes eaten with the skin provide nearly half of the Daily Value for vitamin C and are one of the best sources of potassium and fiber. (See what I mean about the fiber prejudice?)

A medium-sized potato only gives you about 100 calories and it provides complex carbohydrates for long-lasting energy. It is also very filling.

One warning: the potato does rank high on the Glycemic Index (GI). This is a system (of particular value to diabetics) that assigns a number to foods based on their ability to increase blood glucose. Eating a plain potato can definitely cause your blood sugar to spike.

However, after an extensive review, the American Diabetes Association concluded that, for people with diabetes, the total amount of carbohydrates rather than the type, determines the blood sugar/glycemic response. So, common toppings such as cheese, broccoli, butter, salsa or vinegar may actually lower the combined GI.

So, to eat or not to eat? “All things in moderation.” Half a baked potato with chives and herb seasoning sounds healthy to me.  A super-size of french fries made with trans-fat-filled grease is a whole different thing.

On to eggs.

It’s all about the cholesterol, isn’t it?  There is clearly a link between the levels of cholesterol in your bloodstream (serum cholesterol) and your risk for heart attack. What is far less clear is the link between the cholesterol that we eat and those same serum cholesterol levels.

Way back when eggs were getting the worst criticism it was thought that all cholesterol was bad for you. Of course, we now know that that’s not true. There are both harmful and helpful variations.

In truth, it’s our bodies that actually produce the majority of the cholesterol found in the bloodstream. It is absolutely vital to quite a number of bodily processes and is a key component of cell membranes.

It’s looking more and more like the real villains in dietary cholesterol are saturated fats and the artificially altered oils known as trans fats. There are numerous studies proving a link between increased ingestion of trans fats and rises in both serum cholesterol levels of the bad variety and increased risk of heart attack and stroke.

Now for the surprise. Recent research suggests that the cholesterol from eggs may have much less of a negative effect on bloodstream levels of cholesterol than was previously thought; some research suggests it may actually raise the level of “good” cholesterol in the blood and lower the “bad!”

Eggs are without question the best source of protein going.  They also contain more than a dozen valuable vitamins and minerals. Ironically, the group who would benefit the most from a diet including a reasonable amount of eggs is the elderly, and they are precisely the group who are most frequently placed on diets restricting their egg intake.

Bear in mind that the jury is still officially out on this one. However, even some conservative health organizations are beginning to recognize that the benefits of eating several eggs per week probably outweigh the risks. I, for one, will not be surprised to see them fully rehabilitated over the next ten years as more research is completed.

Finally, the truth about fiber.

While most western diets are certainly skimpy on fiber, the typical recommendation is to wolf down some wheat bran and call it a day. While wheat bran and whole wheat products are certainly good sources of fiber, they are far from being your only good choice.

Wheat bran is an insoluble fiber, meaning it passes through the entire digestive process largely unchanged. Insoluble fiber’s important functions are to move bulk through your system efficiently and to help balance the pH in the intestines.

There are many other good sources of insoluble fiber besides wheat and other grains, including fruit and vegetable skins (remember that yummy potato?) and cellulose-filled veggies like green beans and dark green leafy vegetables. Variety is the key here.

A word to the wise: if you have any chronic digestive troubles, you are best to avoid wheat, corn and nut products, regardless of the fiber content. Get the bulk you need from the gentler fruit and vegetable crowd.

And now, the unsung hero of the fiber universe: soluble fiber. This is found in oatmeal, rice, barley, most dried peas and beans, and most fruits. (Now you know why an apple a day keeps the doctor away: the peel has the insoluble fiber, while the flesh has the soluble.) Its important functions include binding with fatty acids and prolonging stomach emptying time so that sugars are released and absorbed more slowly.

That means it helps lower the amount of cholesterol released to your bloodstream. It also means that it helps your stomach process sugar more slowly, which is important to diabetics in particular. For the rest of us, it makes us feel full and satisfied for longer.

Oatmeal in particular is showing itself to be a great addition to a healthy lifestyle.  It combines all the great attributes of a soluble fiber with a lot of versatility in preparation. It is proven to reduce serum cholesterol levels for many people, particularly when paired with a reduced-fat diet. As little as two-thirds of a cup per day has been shown to make a difference. It also contains protein and has one of the highest levels of dietary iron per calorie (really important if you restrict your intake of red meat).

So, which type of fiber is better?  Neither. We need both types of fiber in our diet, since they both serve different functions. Again, “moderation in all things” should be our guide. Nearly all foods made by nature have some good qualities. Take bacon for instance. Though it is miserably high in fat and salt, it is also high in protein, and has the advantage of being so intensely flavored that one cooked strip can often flavor an entire dish. That’s pretty impressive for something that only gives you 20-30 calories.

So when your favorite magazine touts fresh tomatoes as a cure for cancer, then tells you to eliminate iceberg lettuce from your diet because it’s a nutritional zero, take it all with a grain of salt.

Oh, no. Wait.

Isn’t salt bad for you too?!

*grins*